Sensible and latent heat fluxes in the atmospheric surface layer over the equatorial Atlantic (Appendix)

During a four weeks anchoring station of R.V. ,,Meteor" on the equator at 30° W longitude, vertical profiles of wind, temperature, and humidity were measured by means of a meteorological buoy carrying a mast of 10 m height. After eliminating periods of instrumental failure, 18 days are available for the investigation of the diurnal variations of the meteorological parameters and 9 days for the investigation of the vertical heat fluxes. The diurnal variations of the above mentioned quantities are caused essentially by two periodic processes: the 24-hourly changing solar energy supply and the 12-hourly oscillation of air pressure, which both originate in the daily rotation of the earth. While the temperature of the water and of the near water layers of the air show a 24 hours period in their diurnal course, the wind speed, as a consequence of the pressure wave, has a 12 hours period, which is also observable in evaporation and, consequently, in the water vapor content of the surface layer. Concerning the temperature, a weak dependence of the daily amplitude on height was determined. Further investigation of the profiles yields relations between the vertical gradients of wind, temperature, and water vapor and the wind speed, the difference between sea and air of temperature and water vapor, respectively, thus giving a contribution to the problem of parameterizing the vertical fluxes. Mean profile coefficients for the encountered stabilities, which were slightly unstable, are presented, and correction terms are given due to the fact that the conditions at the very surface are not sufficiently represented by measuring in a water depth of 20 cm and assuming water vapor saturation. This is especially true for the water vapor content, where the relation between the gradient and the air-sea difference suggests a reduction of relative humidity to appr. 96% at the very surface, if the gradients are high. This effect may result in an overestimation of the water vapor flux, if a ,,bulk"-formula is used. Finally sensible and latent heat fluxes are computed by means of a gradient-formula. The influence of stability on the transfer process is taken into account. As the air-sea temperature differences are small, sensible heat plays no important role in that region, but latent heat shows several interesting features. Within the measuring period of 18 days, a regular variation by a factor of ten is observed. Unperiodic short term variations are superposed by periodic diurnal variations. The mean diurnal course shows a 12-hours period caused by the vertical wind speed gradient superposed by a 24-hours period due to the changing stabilities. Mean values within the measuring period are 276 ly/day for latent heat and 9.41y/day for sensible heat.

Seawater carbonate chemistry and biological processes during experiments with the spider crab Hyas araneus in Kongsfjorden, Svalbard, 2009

With global climate change, ocean warming and acidification occur concomitantly. In this study, we tested the hypothesis that increasing CO2 levels affect the acid-base balance and reduce the activity capacity of the Arctic spider crab Hyas araneus, especially at the limits of thermal tolerance. Crabs were acclimated to projected oceanic CO2 levels for 12 days (today: 380, towards the year 2100: 750 and 1,120 and beyond: 3,000 ?atm) and at two temperatures (1 and 4 °C). Effects of these treatments on the righting response (RR) were determined (1) at acclimation temperatures followed by (2) righting when exposed to an additional acute (15 min) heat stress at 12 °C. Prior to (resting) and after the consecutive stresses of combined righting activity and heat exposure, acid-base status and lactate contents were measured in the haemolymph. Under resting conditions, CO2 caused a decrease in haemolymph pH and an increase in oxygen partial pressure. Despite some buffering via an accumulation of bicarbonate, the extracellular acidosis remained uncompensated at 1 °C, a trend exacerbated when animals were acclimated to 4 °C. The additional combined exposure to activity and heat had only a slight effect on blood gas and acid-base status. Righting activity in all crabs incubated at 1 and 4 °C was unaffected by elevated CO2 levels or acute heat stress but was significantly reduced when both stressors acted synergistically. This impact was much stronger in the group acclimated at 1 °C where some individuals acclimated to high CO2 levels stopped responding. Lactate only accumulated in the haemolymph after combined righting and heat stress. In the group acclimated to 1 °C, lactate content was highest under normocapnia and lowest at the highest CO2 level in line with the finding that RR was largely reduced. In crabs acclimated to 4 °C, the RR was less affected by CO2 such that activity caused lactate to increase with rising CO2 levels. In line with the concept of oxygen and capacity limited thermal tolerance, all animals exposed to temperature extremes displayed a reduction in scope for performance, a trend exacerbated by increasing CO2 levels. Additionally, the differences seen between cold- and warm-acclimated H. araneus after heat stress indicate that a small shift to higher acclimation temperatures also alleviates the response to temperature extremes, indicating a shift in the thermal tolerance window which reduces susceptibility to additional CO2 exposure.

Design and Optimization of Power Delivery and Distribution Systems Using Evolutionary Computation Techniques

Nowadays computing platforms consist of a very large number of components that require to be supplied with diferent voltage levels and power requirements. Even a very small platform, like a handheld computer, may contain more than twenty diferent loads and voltage regulators. The power delivery designers of these systems are required to provide, in a very short time, the right power architecture that optimizes the performance, meets electrical specifications plus cost and size targets. The appropriate selection of the architecture and converters directly defines the performance of a given solution. Therefore, the designer needs to be able to evaluate a significant number of options in order to know with good certainty whether the selected solutions meet the size, energy eficiency and cost targets. The design dificulties of selecting the right solution arise due to the wide range of power conversion products provided by diferent manufacturers. These products range from discrete components (to build converters) to complete power conversion modules that employ diferent manufacturing technologies. Consequently, in most cases it is not possible to analyze all the alternatives (combinations of power architectures and converters) that can be built. The designer has to select a limited number of converters in order to simplify the analysis. In this thesis, in order to overcome the mentioned dificulties, a new design methodology for power supply systems is proposed. This methodology integrates evolutionary computation techniques in order to make possible analyzing a large number of possibilities. This exhaustive analysis helps the designer to quickly define a set of feasible solutions and select the best trade-off in performance according to each application. The proposed approach consists of two key steps, one for the automatic generation of architectures and other for the optimized selection of components. In this thesis are detailed the implementation of these two steps. The usefulness of the methodology is corroborated by contrasting the results using real problems and experiments designed to test the limits of the algorithms.

Combined determination of sharing and freeness of program variables through abstract interpretation

In this paper, abstract interpretation algorithms are described for computing the sharmg as well as the freeness information about the run-time instantiations of program variables. An abstract domain is proposed which accurately and concisely represents combined freeness and sharing information for program variables. Abstract unification and all other domain-specific functions for an abstract interpreter working on this domain are presented. These functions are illustrated with an example. The importance of inferring freeness is stressed by showing (1) the central role it plays in non-strict goal independence, and (2) the improved accuracy it brings to the analysis of sharing information when both are computed together. Conversely, it is shown that keeping accurate track of sharing allows more precise inference of freeness, thus resulting in an overall much more powerful abstract interpreter.

Electrodynamic Tether at Jupiter I: Capture operation and constraints

Tethered spacecraft missions to the Jovian system suit the use of electrodynamic tethers because: 1) magnetic stresses are 100 times greater than at the Earth; 2) the stationary orbit is one-third the relative distance for Earth; and 3) moon Io is a nearby giant plasma source. The (bare) tether is a reinforced aluminum foil with tens of kilometer length L and a fraction of millimeter thickness h, which collects electrons as an efficient Langmuir probe and can tap Jupiter’s rotational energy for both propulsion and power. In this paper, the critical capture operation is explicitly formulated in terms of orbit geometry and established magnetic and thermal plasma models. The design parameters L and h and capture perijove radius rp face opposite criteria independent of tape width. Efficient capture requires a low rp and a high L 3/2/h ratio. However, combined bounds on tether bowing and tether tensile stress, arising from a spin made necessary by the low Jovian gravity gradient, require a high rp and a low L 5/2/h ratio. Bounds on tether temperature again require a high rp and a low L 3/8/(tether emissivity)1/4 ratio. Optimal design values are discussed.

Testing JEFF-3.1.1 and ENDF/B-VII.1 Decay and Fission Yield Nuclear Data Libraries with Fission Pulse Neutron Emission and Decay Heat Experiments

The aim of this work is to test the present status of Evaluated Nuclear Decay and Fission Yield Data Libraries to predict decay heat and delayed neutron emission rate, average neutron energy and neutron delayed spectra after a neutron fission pulse. Calculations are performed with JEFF-3.1.1 and ENDF/B-VII.1, and these are compared with experimental values. An uncertainty propagation assessment of the current nuclear data uncertainties is performed.

Laminar counterflow parallel-plate heat exchangers: Exact and approximate solutions

Multilayered, counterflow, parallel-plate heat exchangers are analyzed numerically and theoretically. The analysis, carried out for constant property fluids, considers a hydrodynamically developed laminar flow and neglects longitudinal conduction both in the fluid and in the plates. The solution for the temperature field involves eigenfunction expansions that can be solved in terms of Whittaker functions using standard symbolic algebra packages, leading to analytical expressions that provide the eigenvalues numerically. It is seen that the approximate solution obtained by retaining the first two modes in the eigenfunction expansion provides an accurate representation for the temperature away from the entrance regions, specially for long heat exchangers, thereby enabling simplified expressions for the wall and bulk temperatures, local heat-transfer rate, overall heat-transfer coefficient, and outlet bulk temperatures. The agreement between the numerical and theoretical results suggests the possibility of using the analytical solutions presented herein as benchmark problems for computational heat-transfer codes.

Exact solution for the conjugate fluid-fluid problem in the thermal entrance region of laminar counterflow heat exchangers

A generalized Lévêque solution is presented for the conjugate fluid–fluid problem that arises in the thermal entrance region of laminar counterflow heat exchangers. The analysis, carried out for constant property fluids, assumes that the Prandtl and Peclet numbers are both large compared to unity, and neglects axial conduction both in the fluids and in the plate, assumed to be thermally thin. Under these conditions, the thermal entrance region admits an asymptotic self-similar description where the temperature varies as a power ϳ of the axial distance, with the particularity that the self-similarity exponent must be determined as an eigenvalue by solving a transcendental equation arising from the requirement of continuity of heat fluxes at the heat conducting wall. Specifically, the analysis reveals that j depends only on the lumped parameter ƙ = (A2/A1)1/3 (α1/α2)1/3(k2/k1), defined in terms of the ratios of the wall velocity gradients, A, thermal diffusivities, α i, and thermal conductivities,k i, of the fluids entering, 1, and exiting, 2, the heat exchanger. Moreover, it is shown that for large (small) values of K solution reduces to the classical first (second) Lévêque solution. Closed-form analytical expressions for the asymptotic temperature distributions and local heat-transfer rate in the thermal entrance region are given and compared with numerical results in the counterflow parallel-plate configuration, showing very good agreement in all cases.

Thermal, stress, and traps effects in AlGaN/GaN HEMTs

GaN y AlN son materiales semiconductores piezoeléctricos del grupo III-V. La heterounión AlGaN/GaN presenta una elevada carga de polarización tanto piezoeléctrica como espontánea en la intercara, lo que genera en su cercanía un 2DEG de grandes concentración y movilidad. Este 2DEG produce una muy alta potencia de salida, que a su vez genera una elevada temperatura de red. Las tensiones de puerta y drenador provocan un stress piezoeléctrico inverso, que puede afectar a la carga de polarización piezoeléctrica y así influir la densidad 2DEG y las características de salida. Por tanto, la física del dispositivo es relevante para todos sus aspectos eléctricos, térmicos y mecánicos. En esta tesis se utiliza el software comercial COMSOL, basado en el método de elementos finitos (FEM), para simular el comportamiento integral electro-térmico, electro-mecánico y electro-térmico-mecánico de los HEMTs de GaN. Las partes de acoplamiento incluyen el modelo de deriva y difusión para el transporte electrónico, la conducción térmica y el efecto piezoeléctrico. Mediante simulaciones y algunas caracterizaciones experimentales de los dispositivos, hemos analizado los efectos térmicos, de deformación y de trampas. Se ha estudiado el impacto de la geometría del dispositivo en su auto-calentamiento mediante simulaciones electro-térmicas y algunas caracterizaciones eléctricas. Entre los resultados más sobresalientes, encontramos que para la misma potencia de salida la distancia entre los contactos de puerta y drenador influye en generación de calor en el canal, y así en su temperatura. El diamante posee une elevada conductividad térmica. Integrando el diamante en el dispositivo se puede dispersar el calor producido y así reducir el auto-calentamiento, al respecto de lo cual se han realizado diversas simulaciones electro-térmicas. Si la integración del diamante es en la parte superior del transistor, los factores determinantes para la capacidad disipadora son el espesor de la capa de diamante, su conductividad térmica y su distancia a la fuente de calor. Este procedimiento de disipación superior también puede reducir el impacto de la barrera térmica de intercara entre la capa adaptadora (buffer) y el substrato. La muy reducida conductividad eléctrica del diamante permite que pueda contactar directamente el metal de puerta (muy cercano a la fuente de calor), lo que resulta muy conveniente para reducir el auto-calentamiento del dispositivo con polarización pulsada. Por otra parte se simuló el dispositivo con diamante depositado en surcos atacados sobre el sustrato como caminos de disipación de calor (disipador posterior). Aquí aparece una competencia de factores que influyen en la capacidad de disipación, a saber, el surco atacado contribuye a aumentar la temperatura del dispositivo debido al pequeño tamaño del disipador, mientras que el diamante disminuiría esa temperatura gracias a su elevada conductividad térmica. Por tanto, se precisan capas de diamante relativamente gruesas para reducer ele efecto de auto-calentamiento. Se comparó la simulación de la deformación local en el borde de la puerta del lado cercano al drenador con estructuras de puerta estándar y con field plate, que podrían ser muy relevantes respecto a fallos mecánicos del dispositivo. Otras simulaciones se enfocaron al efecto de la deformación intrínseca de la capa de diamante en el comportamiento eléctrico del dispositivo. Se han comparado los resultados de las simulaciones de la deformación y las características eléctricas de salida con datos experimentales obtenidos por espectroscopía micro-Raman y medidas eléctricas, respectivamente. Los resultados muestran el stress intrínseco en la capa producido por la distribución no uniforme del 2DEG en el canal y la región de acceso. Además de aumentar la potencia de salida del dispositivo, la deformación intrínseca en la capa de diamante podría mejorar la fiabilidad del dispositivo modulando la deformación local en el borde de la puerta del lado del drenador. Finalmente, también se han simulado en este trabajo los efectos de trampas localizados en la superficie, el buffer y la barrera. Las medidas pulsadas muestran que tanto las puertas largas como las grandes separaciones entre los contactos de puerta y drenador aumentan el cociente entre la corriente pulsada frente a la corriente continua (lag ratio), es decir, disminuir el colapse de corriente (current collapse). Este efecto ha sido explicado mediante las simulaciones de los efectos de trampa de superficie. Por su parte, las referidas a trampas en el buffer se enfocaron en los efectos de atrapamiento dinámico, y su impacto en el auto-calentamiento del dispositivo. Se presenta también un modelo que describe el atrapamiento y liberación de trampas en la barrera: mientras que el atrapamiento se debe a un túnel directo del electrón desde el metal de puerta, el desatrapamiento consiste en la emisión del electrón en la banda de conducción mediante túnel asistido por fonones. El modelo también simula la corriente de puerta, debida a la emisión electrónica dependiente de la temperatura y el campo eléctrico. Además, también se ilustra la corriente de drenador dependiente de la temperatura y el campo eléctrico. ABSTRACT GaN and AlN are group III-V piezoelectric semiconductor materials. The AlGaN/GaN heterojunction presents large piezoelectric and spontaneous polarization charge at the interface, leading to high 2DEG density close to the interface. A high power output would be obtained due to the high 2DEG density and mobility, which leads to elevated lattice temperature. The gate and drain biases induce converse piezoelectric stress that can influence the piezoelectric polarization charge and further influence the 2DEG density and output characteristics. Therefore, the device physics is relevant to all the electrical, thermal, and mechanical aspects. In this dissertation, by using the commercial finite-element-method (FEM) software COMSOL, we achieved the GaN HEMTs simulation with electro-thermal, electro-mechanical, and electro-thermo-mechanical full coupling. The coupling parts include the drift-diffusion model for the electron transport, the thermal conduction, and the piezoelectric effect. By simulations and some experimental characterizations, we have studied the device thermal, stress, and traps effects described in the following. The device geometry impact on the self-heating was studied by electro-thermal simulations and electrical characterizations. Among the obtained interesting results, we found that, for same power output, the distance between the gate and drain contact can influence distribution of the heat generation in the channel and thus influence the channel temperature. Diamond possesses high thermal conductivity. Integrated diamond with the device can spread the generated heat and thus potentially reduce the device self-heating effect. Electro-thermal simulations on this topic were performed. For the diamond integration on top of the device (top-side heat spreading), the determinant factors for the heat spreading ability are the diamond thickness, its thermal conductivity, and its distance to the heat source. The top-side heat spreading can also reduce the impact of thermal boundary resistance between the buffer and the substrate on the device thermal behavior. The very low electrical conductivity of diamond allows that it can directly contact the gate metal (which is very close to the heat source), being quite convenient to reduce the self-heating for the device under pulsed bias. Also, the diamond coated in vias etched in the substrate as heat spreading path (back-side heat spreading) was simulated. A competing mechanism influences the heat spreading ability, i.e., the etched vias would increase the device temperature due to the reduced heat sink while the coated diamond would decrease the device temperature due to its higher thermal conductivity. Therefore, relative thick coated diamond is needed in order to reduce the self-heating effect. The simulated local stress at the gate edge of the drain side for the device with standard and field plate gate structure were compared, which would be relevant to the device mechanical failure. Other stress simulations focused on the intrinsic stress in the diamond capping layer impact on the device electrical behaviors. The simulated stress and electrical output characteristics were compared to experimental data obtained by micro-Raman spectroscopy and electrical characterization, respectively. Results showed that the intrinsic stress in the capping layer caused the non-uniform distribution of 2DEG in the channel and the access region. Besides the enhancement of the device power output, intrinsic stress in the capping layer can potentially improve the device reliability by modulating the local stress at the gate edge of the drain side. Finally, the surface, buffer, and barrier traps effects were simulated in this work. Pulsed measurements showed that long gates and distances between gate and drain contact can increase the gate lag ratio (decrease the current collapse). This was explained by simulations on the surface traps effect. The simulations on buffer traps effects focused on illustrating the dynamic trapping/detrapping in the buffer and the self-heating impact on the device transient drain current. A model was presented to describe the trapping and detrapping in the barrier. The trapping was the electron direct tunneling from the gate metal while the detrapping was the electron emission into the conduction band described by phonon-assisted tunneling. The reverse gate current was simulated based on this model, whose mechanism can be attributed to the temperature and electric field dependent electron emission in the barrier. Furthermore, the mechanism of the device bias via the self-heating and electric field impact on the electron emission and the transient drain current were also illustrated.

Estudio de las dinámicas de pérdida de peso corporal en los programas de ejercicio físico y nutrición = Study of the dynamics of body weight loss in exercise and nutritional programs

Introducción. La obesidad puede definirse como una enfermedad metabólica crónica de origen multifactorial, lo que provoca trastornos o problemas físicos y psicológicos a la persona, con patologías asociadas que limitan la esperanza de vida y deterioran la calidad de la misma, siendo determinante para sus áreas sociales y laborales. Este trastorno metabólico crónico se caracteriza por una acumulación excesiva de energía en el cuerpo en forma de grasa, lo que lleva a un aumento de peso con respecto al valor esperado por sexo, edad y altura. La gestión y el tratamiento de la obesidad tienen objetivos más amplios que la pérdida de peso e incluyen la reducción del riesgo y la mejora de la salud. Estos pueden ser alcanzados por la pérdida modesta de peso (es decir, 10.5% del peso corporal inicial), la mejora del contenido nutricional de la dieta y un modesto incremento en la actividad física y condición física. La dieta es uno de los métodos más populares para perder peso corporal. El ejercicio es otra alternativa para perder peso corporal. El aumento de ejercicio provoca un desequilibrio cuando se mantiene la ingesta calórica. También tiene ventajas, como la mejora del tono muscular, la capacidad cardiovascular, fuerza y flexibilidad, aumenta el metabolismo basal y mejora el sistema inmunológico. Objetivos. El objetivo de esta tesis es contribuir en un estudio de intervención para aclarar la evolución del peso corporal durante una intervención de dieta y ejercicio. Para ello, se evaluaron los efectos de la edad, sexo, índice de masa corporal inicial y el tipo de tratamiento en las tendencias de pérdida de peso. Otro objetivo de la tesis era crear un modelo de regresión lineal múltiple capaz de predecir la pérdida de peso corporal después del periodo de intervención. Y, por último, determinar el efecto sobre la composición corporal (peso corporal, índice de masa corporal, la masa grasa, y la masa libre de grasa) de las diferentes intervenciones basadas en ejercicios (fuerza, resistencia, resistencia combinada con fuerza, y las recomendaciones de actividad física (grupo control)) en combinación con dieta de adultos con sobrepeso y obesidad, después de la intervención, así como los cambios de la composición corporal 3 años más tarde. Diseño de la investigación. Los datos empleados en el análisis de esta tesis son parte del proyecto “Programas de Nutrición y Actividad Física para el tratamiento de la obesidad” (PRONAF). El proyecto PRONAF es un estudio clínico sobre programas de nutrición y actividad física para el sobrepeso y la obesidad, desarrollado en España durante varios años de intervención. Fue diseñado, en parte, para comparar diferentes tipos de intervención, con el objetivo de evaluar su impacto en las dinámicas de pérdida de peso, en personas con sobrepeso y obesidad. Como diseño experimental, el estudio se basó en una restricción calórica, a la que, en algunos casos, se le añadió un protocolo de entrenamiento (fuerza, resistencia, o combinado, en igualdad de volumen e intensidad). Las principales variables para la investigación que comprende esta tesis fueron: el peso corporal y la composición corporal (masa grasa y masa libre de grasa). Conclusiones. En esta tesis, para los programas de pérdida de peso en personas con sobrepeso y obesidad con un 25-30% de la restricción calórica, el peso corporal se redujo significativamente en ambos sexos, sin tener en cuenta la edad y el tipo de tratamiento seguido. Según los resultados del estudio, la pérdida de peso realizada por un individuo (hombre o mujer) durante los seis meses puede ser representada por cualquiera de las cinco funciones (lineal, potencial, exponencial, logarítmica y cuadrática) en ambos sexos, siendo la cuadrática la que tiende a representarlo mejor. Además, se puede concluir que la pérdida de peso corporal se ve afectada por el índice de masa corporal inicial y el sexo, siendo mayor para las personas obesas que para las de sobrepeso, que muestran diferencias entre sexos sólo en la condición de sobrepeso. Además, es posible calcular el peso corporal final de cualquier participante involucrado en una intervención utilizando la metodología del proyecto PRONAF sólo conociendo sus variables iniciales de composición corporal. Además, los cuatro tipos de tratamientos tuvieron resultados similares en cambios en la composición corporal al final del período de intervención, con la única excepción de la masa libre de grasa, siendo los grupos de entrenamiento los que la mantuvieron durante la restricción calórica. Por otro lado, sólo el grupo combinado logra mantener la reducción de la masa grasa (%) 3 años después del final de la intervención. ABSTRACT Introduction. Obesity can be defined as a chronic metabolic disease from a multifactorial origin, which leads to physical and psychological impacts to the person, with associated pathologies that limit the life expectancy and deteriorate the quality of it, being determinant for the social and labor areas of the person. This chronic metabolic disorder is characterized by an excessive accumulation of energy in the body as fat, leading to increased weight relative to the value expected by sex, age and height. The management and treatment of obesity have wider objectives than weight loss alone and include risk reduction and health improvement. These may be achieved by modest weight loss (i.e. 5–10% of initial body weight), improved nutritional content of the diet and modest increases in physical activity and fitness. Weight loss through diet is one of the most popular approaches to lose body weight. Exercise is another alternative to lose body weight. The increase of exercise causes an imbalance when the caloric intake is maintained. It also has advantages such as improved muscle tone, cardiovascular fitness, strength and flexibility, increases the basal metabolism and improves immune system. Objectives. The aim of this thesis is to contribute with an interventional study to clarify the evolution of the body weight during a diet and exercise intervention. For this, the effects of age, sex, initial body mass index and type of treatment on weight loss tendencies were evaluated. Another objective of the thesis was to create a multiple linear regression model able to predict the body weight loss after the intervention period. And, finally, to determine the effect upon body composition (body weight, body mass index, fat mass, and fat-free mass of different exercise-based interventions (strength, endurance, combined endurance and strength, and physical activity recommendations group (control group)) combined with diet in overweight and obese adults, after intervention as well as body composition changes 3 years later. Research Design. The data used in the analysis of this thesis are part of the project "Programs of Nutrition and Physical Activity for the treatment of obesity" (PRONAF). The PRONAF project is a clinical trial program about nutrition and physical activity for overweight and obesity, developed in Spain for several years of intervention. It was designed, in part, to compare different types of intervention, in order to assess their impact on the dynamics of weight loss in overweight and obese people. As experimental design, the study was based on caloric restriction, which, in some cases, added a training protocol (strength, endurance, or combined in equal volume and intensity). The main research variables comprising this thesis were: body weight and body composition outcomes (fat mass and fat-free mass). Conclusions. In this thesis, for weight loss programs in overweight and obese people with 25-30% of caloric restriction, the body weight was significantly decreased in both sexes, regardless the age and type of followed treatment. According to the results of the study, the weight loss performed by an individual (male or female) during six months can be represented by any of the five functions (linear, power law, exponential, logarithmic and quadratic) in both sexes, being the quadratic one which tends to represent it better. In addition, it can be concluded that the body weight loss is affected by the initial body mass index and sex condition, being greater for the obese people than for the overweight one, showing differences between sexes only in the overweight condition. Moreover, it is possible to calculate the final body weight of any participant engaged in an intervention using the PRONAF Project methodology only knowing their initial body composition variables. Furthermore, the four types of treatments had similar results on body composition changes at the end of the intervention period, with the only exception of fat-free mass, being the training groups the ones that maintained it during the caloric restriction. On the other hand, only the combined group achieved to maintain the fat mass (%) reduced 3 years after the end of the intervention.

Combined effect of tumor necrosis factor-related apoptosis-inducing ligand and ionizing radiation in breast cancer therapy

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potent endogenous activator of the cell death pathway and functions by activating the cell surface death receptors 4 and 5 (DR4 and DR5). TRAIL is nontoxic in vivo and preferentially kills neoplastically transformed cells over normal cells by an undefined mechanism. Radiotherapy is a common treatment for breast cancer as well as many other cancers. Here we demonstrate that ionizing radiation can sensitize breast carcinoma cells to TRAIL-induced apoptosis. This synergistic effect is p53-dependent and may be the result of radiation-induced up-regulation of the TRAIL-receptor DR5. Importantly, TRAIL and ionizing radiation have a synergistic effect in the regression of established breast cancer xenografts. Changes in tumor cellularity and extracellular space were monitored in vivo by diffusion-weighted magnetic resonance imaging (diffusion MRI), a noninvasive technique to produce quantitative images of the apparent mobility of water within a tissue. Increased water mobility was observed in combined TRAIL- and radiation-treated tumors but not in tumors treated with TRAIL or radiation alone. Histological analysis confirmed the loss of cellularity and increased numbers of apoptotic cells in TRAIL- and radiation-treated tumors. Taken together, our results provide support for combining radiation with TRAIL to improve tumor eradication and suggest that efficacy of apoptosis-inducing cancer therapies may be monitored noninvasively, using diffusion MRI.

Critical behavior of the specific heat in glass formers

We show numeric evidence that, at low enough temperatures, the potential energy density of a glass-forming liquid fluctuates over length scales much larger than the interaction range. We focus on the behavior of translationally invariant quantities. The growing correlation length is unveiled by studying the finite-size effects. In the thermodynamic limit, the specific heat and the relaxation time diverge as a power law. Both features point towards the existence of a critical point in the metastable supercooled liquid phase.

Exact and analytic-numerical solutions of lagging models of heat transfer in a semi-infinite medium

Different non-Fourier models of heat conduction have been considered in recent years, in a growing area of applications, to model microscale and ultrafast, transient, nonequilibrium responses in heat and mass transfer. In this work, using Fourier transforms, we obtain exact solutions for different lagging models of heat conduction in a semi-infinite domain, which allow the construction of analytic-numerical solutions with prescribed accuracy. Examples of numerical computations, comparing the properties of the models considered, are presented.

A Survey on FPGA-Based Sensor Systems: Towards Intelligent and Reconfigurable Low-Power Sensors for Computer Vision, Control and Signal Processing

The current trend in the evolution of sensor systems seeks ways to provide more accuracy and resolution, while at the same time decreasing the size and power consumption. The use of Field Programmable Gate Arrays (FPGAs) provides specific reprogrammable hardware technology that can be properly exploited to obtain a reconfigurable sensor system. This adaptation capability enables the implementation of complex applications using the partial reconfigurability at a very low-power consumption. For highly demanding tasks FPGAs have been favored due to the high efficiency provided by their architectural flexibility (parallelism, on-chip memory, etc.), reconfigurability and superb performance in the development of algorithms. FPGAs have improved the performance of sensor systems and have triggered a clear increase in their use in new fields of application. A new generation of smarter, reconfigurable and lower power consumption sensors is being developed in Spain based on FPGAs. In this paper, a review of these developments is presented, describing as well the FPGA technologies employed by the different research groups and providing an overview of future research within this field.